Fluid press



Jan. 6,1931.

H. C. HOTTEL Nov. '7, 1928 Patented Jan. 6, 1931 UNITED m Hon 0. uor'rnn, or cairnmnemmassacnnsnrrs mm runes Application fled November 7, 1928. Serial No."317, 805.

This invention relates bro'adly'to improve-f ments in fluid-pressure presses or jacks and more specifically to pres'sesfor formingplas tic materials in molds.

In. the shaping ofplastic. materials in V molds, it is customary to employ a press for forcing or compressing the material into the mold, the press acting in one direction for accomplishing this step". \Vhen the material,

the mold and core, or the position of the press is such that a force is required to return thepiston toits initial position, it is customary either to rely on gravity or to place in engagement with the piston of the press a fluid-- pressure jack, or the like, which will act in the opposite direction to return the piston'to its starting position. Gravity frequently is insufficient toreturn the ram, at least with adequate speed, for quantity production work, while the use of an additional unit,

such as an overhead fluid-pressure jack when t-ion is to provide a work performing unit of the above mentioned type which possesses the further advantagethat the pressure exerted during the power or the material pressing stroke is greater for a given piston diameter and hydraulic pressure than in the case of a simple press.

Another object of the invention is to proprovide a fluid-pressure press or jackwhich is of exceedingly simple construction and which may be expeditiously taken apart to permit repairs, such as the renewal of packing or the like.

Other objects and advantages of the invention will be apparent during the course of the following description.

In the accompanying drawing forming a part of this specification and in which like numerals are employed to designate like parts throughout the same Figure 1 is a vertical sectional View of a taken through fluid-pressure invention, and V Figure 2 1s a press or jack embodying this transverse sectional view the structure shown in Figure1. I

Referring to a preferredembodiment of the invention shown in the: accompanying drawing, the numeral 5 designates a cylinder closed at one end by a wall 6 which is extended radially to form a supporting flange 7. The cylinder bore is increased-in diametera t 8'to form a seat for a packing ring 9 held in place by a compressing ring 10. v

The ring 10 is of angular formation in cross section to provide a packing "engaging flange 11 which'is forced axially of the cylinder by means of bolts, or the like, 12 threaded into the end portion ofthe cylinder 5.

- The end wall 6' of the cylinder is formed with an aperture 13 enlarged at 14 to receive the flanged end 15 of a rod 16 which projects axially through .the interior of the cylinder 5. Bolts,-or the like, 17 are. employed for connecting the -rodj16;to the cylinder wall 6. "It is to be understood that this rod may be formed desired. A body 18 is shaped exteriorly to properly fit within the bore of the cylinder 5 for axial integral with the wall-6 if so movement therein. It is to be understood that the packing, ring 9 will prevent leakagehetween the walls of the body 18 and the cylinder 5. This body will be termedv a combined movable piston and cylinder structure in view of the fact that it acts as a movable piston for the cylinder 5 and as a movable cylinder for a piston, which will be described at a later point, fastened to the rod 16. This combined piston and cylinder structure includes an axial bore 19 apertured at 20 for slidably receiving the rod 16. The aperture 20 is increased in diameter to form a pocket to receive a packing ring 21 held in place by the compressing ring 22. This ring is adjustably secured to the structure 18 by means of bolts or'the like 23.

The free end of the rod 16 is reduced and externally threaded to receive the sectional piston head 24 which includes the mating sections 25 and 26. The adjacent faces of Es PATENTTQFFI'CE 1 Lift.

recessed 'at'30 to accommodate the piston head securing nut 28and the projectingend portion of the rod 16. The plug isfi'an'ged at 31 to accommodate the securing bolts 32,, the said bolts thereby being arranged out-"" connection 7 side of the wall of the bore 19. i

It now will be noted that the structure above described forms an expansiblestructure including an expansible chamber33 be-- tween the inner end' of the body 118 and the wall 6, a secondexpansible chamber 34: be-

tween the inner face ofthe piston head 2d and the ring' or abutment 22, and a third expansible chamber 34c between the outer face of thepiston 24 and the plug or abutment 29. For the purpose of simultaneously admitting fluid-pressure into the expansible chamber 33 and the expansible chamber 34a, a connection '35 communicates with the chamber 33 and a passageway 36 is formed in the wall of the combined piston and cylinder structure 18. o This passageway 36 extends from the innerface of the structure 18 to the outer end portion of the bore 19, entering the'expansible chamber 34a adjacent to the plug 29. Any suitable form of .valve structure, not shown, maybe inserted in the connection 35 to permit this connection to be selectively supplied with fluid-pressure 'or' placed in a direct communication with theatmosphere for exhausting the two cham-' bers.

For the purpose of supplying fluid-pres sure to the expansible chamber 34, the rod 16 is provided with a passageway 37 which communicates at its outerend with the said chamber 34 and at its inner, end with a connection 38 extendingthrough the cylinder 5 to the exterior thereof. A suitable packing structure 39 prevents'leakage around the con nection 38. I p v The operation of this'device may be described as follows: For the purpose of expanding the structure, that is, causing the combined piston and cylinder structure 18 to move axially outwardly with respect to the.

cylinder 5, fluid-pressure'is admitted to the chambers 33 and 34a through the connection 35 and the passageway 36, respectively. It

will be noted that during this stroke or' movement of the structure 18 greater pres sure is exerted for a given plston diameter and hydraulic pressure than in thecase of a simple press or jack. The total area used in calculating the force tending to move thestructure 18 is. the inside end areaof the" structure 18, minus thecross sectional area of the rod 16, plusthe end area of the stationary piston head 24. d

For forcibly returning the structure 18 to its innermost or starting position, the connection 35 is placed in communication with the atmosphere -for exhausting thechambers 33 and-j3 lz't,:. andI'jfluid-PresSure is admitted to thechamber 34 by means of the passageway 37 and the connection 38. It will be liOtEClthat duringthe' 'upward movement of the combined structure 18, the chamber 34 is exhausted throughthe passageway 37 and "It ism be misstated that the form of this invention herewith shown and described is to be taken as aypreferred example of; the

same,-an d that various changes in the shape,

size and arrangement oflparts may be re- .sorted to. without departing from the spirit of the invent-ionor the ,scopeof' thesubjoinedclaim; I

.Iclaimz 1 A d'eviceof the type described comprising a cylinderclosed at its inner end and open at its outer end, an abutment fixed with' respectto said cylinder in spaced relation to the closed'inner'end thereof, a ram slidable within said cylinder providing an expansible chamber". between the closed: inner end of said cylinder and the adjacent end of said ram, said ram having a bore receiving said, abutment, means closingthe ends of said bore whereby separate 'expansible chambersare provided between said abutment and the inner and outer ends of said'bore, respectively, means whereby fluid-is adapted to be admitted to the chamber between the closed inner, end of said cylinderand the adjacent end of saidram for forcing the ram outward relative to the cylinder, said ram having a duct formed therein provid ing constant communication between said last mentioned chamber and the chamber between said abutment and theclosing means for theouter end of said bore, and means whereby is adapted to be admitted to the chamber between said abutment and theinner end of said bore to effect inward movement of the ram relative to the cylinder.

In testimony whereof ,I hereunto afiix my signature. i

, HOYT GLA'RKE I-IOTTE J;

ltd 

